PrepTest 153

Incorrect. "Of no use" jumps out instantly as way too strong. Frankly, just telling time is probably of some use in predicting astronomical phenomena!

Incorrect. This is a trap some students will fall for, because of the appealing use of "some," indicating a weak answer choice. However, notice that the stimulus doesn't support this. We don't get any information from the stimulus about modern clocks' astronomical functions or their complexity.

Incorrect. Again, this is too strong. "Do not differ appreciably" is another way to say "are pretty much all the same." Just knowing that clocks, overall, have decreased in mechanical complexity over the years because time-keeping functions became more important isn't enough to support such a strong statement about their mechanical similarities.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Other mechanical devices started as simple and got more complex, but in the case of clocks, the earliest were the most complex. That's because they were basically complicated astronomy devices that also told time. Gradually, people started to value telling time more and complicated astronomy functions less.

Strategy Overview:
Like always with "most strongly supported" MBTs, we've got to pay careful attention to logical force. Look for the strongest statements—in this case, "the earliest clocks were also the most complicated" jumps out—and find an answer choice that is weak enough to be supported by those few stronger statements in an overall weak stimulus.

Answer Anticipation:
There aren't any rules in the stimulus, but the closest thing is that one strong-ish statement, "the earliest clocks were also the most complicated." So from that we know that there are at least some clocks today that are less complicated than the earliest clocks. (Notice how weakly we're phrasing that? "All of today's clocks are less complicated than the earliest clocks" would be too strong, since even one modern clock with extremely complex astronomical functions could disprove it.)

Answer Explanation:
A nice weak "some" statement, and it's a variation on our anticipation. This answer restates the correct inference that "some clocks today are less complicated than the earliest clocks." It just adds a little more specificity, while staying appropriately weak. Correct!

Key Takeaway:
Although weak logical force is a key factor in choosing the correct answer on most MSS MBTs, a "some" alone does not a correct answer make. Unless you are so rushed for time as to be guessing, don't just take the first weak answer you see; check to make sure the stimulus actually does support it. Even the weakest conclusions need the support of at least one premise to be valid!

Incorrect. This is way outside the scope of the stimulus. We don't have any premises about the rate of change in the public's astronomy interest level! It could have declined abruptly when Galileo was threatened with torture for promoting heliocenticism, for instance.